The mounting of a disk on a paper substrate is widely used in many fields, e.g. in the disk calculator field in which a disk of sheet material is rotatably mounted on a substrate or within a sleeve to display information through a window in the substrate or cover sheet or at an edge of the article, as a wheel for an article having the configuration of a vehicle in a toy, advertising piece or educational piece, as a rotatable member in a pop up card or book, and in a variety of other applications.
A number of techniques have been provided for mounting the disk on the substrate, the most common of which may be the passage of a spreadable paper fastener or rivet or eyelet through aligned holes in the disk and the substrate.
However, numerous other techniques have been developed when employment of an eyelet or paper fastener is undesirable for economy, safety or convenience.
For example, in my U.S. Pat. No. 4,323,609 of 6 Apr. 1982, I have described a rotatable wheel assembly in which the rotatable disk is mounted upon a substrate, inter alia, by a plurality of tabs which are pressed out of the substrate, pass through an opening in the disk and engage in an opening of the cover member to define a structure between the substrate and the cover member upon which the disk is rotatable.
Other techniques are known in the art as well.
For example, U.S. Pat. No.2,386,082 of 2 Oct. 1945, describes a mounting for a disk in which tabs of a substrate are bent back over the inner perimeter of a disk. A system utilizing two instead of four tabs is described in U.S. Pat. No. 3,321,858 of 30 May 1967, these tabs being lifted from the plane of the substrate and overhanging the inner circumference of the disk which, for this purpose, has an internal diameter less than the diameter of the peripheries of these tabs.
In U.S. Pat. No.1,715,737 of 4 Jun. 1929, the pivot is formed by a pronged fastener permanently attached to the substrate, the prongs of which are passed through a central hole in the disk.
In U.S. Pat. No.3,604,134 of 14 Sep. 1971, the pivot for the disk is formed by a central region thereof broken away from the outer portion of the disk. A similar mounting is provided in U.S. Pat. No.3,939,586 of 24 Feb. 1976.
The mounting for the wheel or disk or the calendar of U.S. Pat. No.2,932,104 is formed by a separate central disk attached by adhesive to the substrate and the cover member.
In U.S. Pat. No.3,103,080 of 10 Sep. 1993, widely spaced tabs are lifted from the substrate to overhang the inner circumference of the disk whose internal diameter is less than the spacing of the tabs.
The price marker of U.S. Pat. No.4,008,533 issued 22 Feb. 1977 provides a disk which can have outwardly deflectable tabs engaging in an opening of the support to journal the disk on the latter. In U.S. Pat. No.2,016,445, bent back tabs engage around the inner circumference of the disk.
A separate bearing piece is secured between the substrate and the cover member in U.S. Pat. No.3,718,519 of 27 Feb. 1973 and is heat sealed in position.
U.S. Pat. No.3,852,900 provides a bearing between male and female formations of the cover and substrate which interfit on assembly and journal the disk or wheel.
In U.S. Pat. No.3,471,956, tabs of the substrate or disk are bent through openings in the other and in U.S. Pat. No.3,468,037, a similar principle is used.
By and large, therefore, the prior art provides a rotatable mounting for a disk or wheel which pushes relatively short tabs through openings in either the support or the wheel so that these tabs project in a manner which makes a flat structure difficult to achieve or creates a problem for stability of the wheel, or provides a central structure bearing structure necessitating complex elements which must be positioned with considerable effort. In some cases the cost of the mounting may preclude use of the particular structure for some applications while in others lack of stability, lack of flatness and the need for additional elements may preclude widespread use of the assemblance method or technique.